Anticreep device for a vehicle



Jan. 16, 1968 T. T. CAGLE 3,363,947

' ANTICREEP DEVICE FOR A VEHICLE Filed Nov. 25, 1966 INVENTOR UnitedStates Patent 3,363,947 ANTICREEP DEVICE FOR A VEHICLE Toby T. Cagle,9418 E. Park, Bellflower, Calif. 90706 Filed Nov. 25, 1966, Ser. No.596,910 7 Claims. (Cl. 303-18) This invention relates to an anticreepdevice or a brake holder for a vehicle and is an improvement on myPatent No. 3,174,808.

An object of my invention is to provide a novel anticreep device whichis actuated by the amount of vacuum in the intake manifold of thevehicle. This invention further relates to an anticreep device where thevehicle is provided with an automatic transmission and will prevent thevehicle from moving forward at a slow speed when the engine is idling orrevolving at relatively slow speeds, and when the vacuum in the intakemanifold is at its maximum.

Another object of my invention is to provide an attachment mountedbetween themaster brake cylinder and the vehicle brakes to retain afixed amount of pressure in the brake lines, so that the brakes are heldin contact with the brake drums with a predetermined pressure, thuspreventing creeping or slow movement of the vehicle.

Another object of my invention is to provide an anti creep device of thecharacter stated which will auto matically release to permit freemovement of the vehicle without a brake drag as soon as the engine isaccelerated.

Another object of my invention resides in the simplicity in constructionof the anticreep device, and also a novel means to release all pressureback to the master brake cylinder as soon as the engine is acceleratedand the vacuum in the intake manifold is reduced.

Other objects, advantages and features of invention may appear from theaccompanying drawing, the subjoined detailed description and theappended claims.

In the drawing:

FIGURE 1 is a vertical sectional view of my anticreep device with theparts shown in one position.

FIGURE 2 is a vertical sectional view of my anticreep device showing theparts in another operative position.

Referring more particularly to the drawing, the numeral 1 indicates anouter housing which is closed on one side by the wall 2, which is boltedto the housing 1 by the bolts or cap screws 3. A cylinder 4 is bolted orotherwise attached to the housing 1 on the side opposite the wall 2. Thecylinder 4 has a nipple 5 attached to the outer end thereof, the purposeof which will be subsequently described.

A fitting 6 extends into the housing 1 by threading into the housing, orby other suitable attaching means. A tube or hose 7 extends from theintake manifold 8 of the engine to the fitting 6, and thus will draw aconstant vacuum in the housing 1 depending upon the rpm, of the engine;that is, at low rpm, the vacuum in the housing 1 will be at its maximum.A diaphragm 9 is mounted inside of the housing 1 and bears against theinner surface of the wall 2 during the minimum pressures within thehousing 1. A rod 10 is mounted on the diaphragm 9 and extends into thecylinder 4 through the inner wall 11 of that cylinder. A head 12 on theinner end of the rod It is provided with small ports 13 extendingtherethrough to permit passage of brake fluid from the master cylinder,as will be subsequently described. A coil spring 14 surrounds the rod 10on the outside of the wall 2, subsequently as shown, and the ten sion ofthis spring can be adjusted by the adjusting nut 15 which is threadedonto the rod 10 and bears against the spring. The spring 14 will thusnot only return the 3,363,947 Patented Jan. 16, 1968 diaphragm 9 to theposition shown in FIGURE 1, but it will also move the head 12 to areleasing position, as will be subsequently described. An air reliefport 16 is provided in the wall 2 to release any air which might beentrapped back of the diaphragm 9'.

A piston 17 is mounted within the cylinder 4 and moves in two directionsin the cylinder, depending upon the action of the rod 16*. The piston 17in one position will seat against the bore 18 in the nipple 5, as shownin FIGURE 2, and is pressed into this seating position by the rod 10 asthe diaphragm 9 is deflected by the vacuum in the intake manifold 8.This position is shown in FIGURE 2. The bore 18 in the nipple 5 isconnected to the brake lines of the usual and well known type, and thebrake lines are attached to the threaded tip 19 when the parts are allassembled. A brake hydraulic fluid fitting 20 extends into the cylinder4 at one end thereof and brake fluid under pressure can be forced intothe cylinder 4 when the master brake cylinder 21 is actuated by thedriver. When the brakes are activated by the driver the engine willnormally be moving at a relatively high r.p.m., which means that thevacuum is at its minimum. Consequently, the parts will be in theposition shown in FIGURE 1; that is, the head 12 will be moved away fromthe piston 17 and, consequently, brake fluid under pressure will by-passthe piston 17 and move into the bore 13, and thence into the brake linesto actuate the brakes. To assist in moving the piston 17 off of itsseat, ports 22 are provided through the piston 17 which will cause apressure build up on one side of the piston to cause it to move awayfrom its seat and thus permit the free flow of fluid into the brakelines. Also fluid flow is permitted through the spring valve 23, alsotermed a Schrader valve. This valve permits fluid flow from left toright, as shown in each of the drawings, but will check flow from rightto left.

When vacuum pressure is at its maximum in the manifold 8 the diaphragm 9will flex, as shown in FIGURE 2, thus pressing the head 12 against thepiston 17 and seating that piston against the nipple 5. Hydraulic fluidunder pressure can then flow through the ports 13 and thence through thevalve 23 and into the: brake lines. If pressure in the master cylinder21 is reduced, then pressure in the brake lines will be maintained tokeep the brakes engaged, since the fluid in these lines is trapped bythe check valve 23 and, consequently, the vehicle Will not creep. Assoon as the vacuum in the manifold 8 is reduced, the diaphragm 9 returnsto the position shown in FIGURE 1, whereupon the head 12 disengages thepiston 17 and the piston then can move away from its seat and thusreleasing pressure in the brake lines so that there is no drag of thebrakes.

Having described my invention, I claim:

1. An anticreep device for a vehicle having a brake master cylinder, anintake manifold and brakes thereon, comprising, a housing, a flexiblediaphragm in said housing, said housing having an intake port connectedto the intake manifold, a cylinder mounted on the housing, a port in thecylinder connected to the master cylinder, said cylinder having a portat one end thereof connected to the brakes, a free floating piston insaid cylinder, a seat in the cylinder engaged by the piston in oneposition of the parts, a check valve means in said piston permittingflow through the piston in one direction, and means on the diaphragmengageable with the piston to seat said piston on deflection of thediaphragm.

2. An anticreep device for a vehicle as recited in claim 1, and springmeans connected to the diaphragm opposing the pull of vacuum in theintake manifold on said diaphragm.

3. An anticreep device for a Vehicle as recited in claim 1, said meanson the diaphragm comprising a rod projecting from the diaphragm, saidrod engaging the piston to seat the same on flexure of the diaphragm.

4. An anticreep device for a vehicle as recited in claim 1, and springmeans connected to the diaphragm opposing the pull of vacuum in theintake manifold on said diaphragm, said means on the diaphragmcomprising a rod projecting from the diaphragm, said rod engaging thepiston to seat the same on flexure of the diaphragm.

5. An anticreep device for a vehicle as recited in claim 1, said pistonbeing positioned between the two ports in said cylinder.

6. An anticreep device for a vehicle as recited in claim 42 1, saidpiston having ports extending longitudinally therethrough.

7. An anticreep device for a vehicle as recited in claim 1, said pistonbeing positioned between the two ports in said cylinder, said pistonhaving ports extending longitudinally therethrough.

References Cited UNITED STATES PATENTS 2,626,026 1/1953 Sherwood et all923 MILTON BUCHLER, Primary Examiner.

J. I. MCLAUGHLIN, Assistant Examiner.

1. AN ANTICREEP DEVICE FOR A VEHICLE HAVING A BRAKE MASTER CYLINDER, ANINTAKE MANIFOLD AND BRAKES THEREON, COMPRISING, A HOUSING, A FLEXIBLEDIAPHRAGM IN SAID HOUSING, SAID HOUSING HAVING AN INTAKE PORT CONNECTEDTO THE INTAKE MANIFOLD, A CYLINDER MOUNTED ON THE HOUSING, A PORT IN THECYLINDER CONNECTED TO THE MASTER CYLINDER, SAID CYLINDER HAVING A PORTAT ONE END THEREOF CONNECTED TO THE BRAKES, A FREE FLOATING PISTON INSAID CYLINDER, A SEAT IN THE CYLINDER ENGAGED BY THE PISTON IN ONEPOSITION OF THE PARTS, A CHECK VALVE MEANS IN SAID PISTON PERMITTINGFLOW THROUGH THE PISTON IN ONE DIRECTION, THE MEANS ON THE DIAPHRAGMENGAGEABLE WITH THE PISTON TO SEAT SAID PISTON ON DEFLECTION OF THEDIAPHRAGM.